OSHA has proposed $545,000 in fines against Dover Chemical, a manufacturer of various antioxidants, flame retardants, dispersing agents and other chemicals for the rubber and plastics industries.

The Nov. 28 citations are the result of an OSHA investigation of Dover Chemical’s manufacturing plant in Dover, involving the breach of a PVC piping system, the agency said. OSHA said it found multiple problems with the plant’s standards for process safety management, which are required of every facility that uses hazardous chemicals.

OSHA designated four of the violations as “willful,” meaning that management either deliberately disregarded federal regulations or was plainly indifferent to worker safety and health.

These violations were failure to correct deficiencies found in compliance audits; not resolving recommendations made during a process hazard analysis; having operating procedures that did not include the consequences for deviating from procedures or the steps necessary to correct deviations; and process safety information that did not detail the construction materials for piping and piping system components.

Of the remaining 43 violations, OSHA designated 41 as “serious” and two as “other than serious.” These included inaccurate operating procedures; inadequate information about the hazards of inadvertently mixing different chemicals; and lack of employee training about process safety management.

OSHA said it placed Dover Chemical in the agency’s Severe Violator Enforcement Program, which mandates targeted follow-up inspections to ensure compliance with the law.

Dover Chemical had 15 days from Nov. 28 to decide whether to comply with the OSHA order, request an informal conference with the agency’s area director or contest the citations before the independent Occupational Safety and Health Review Commission.

Dover Chemical President Dwain S. Colvin could not be reached for comment.